1. Field of the Invention
The present invention relates generally to the field of enclosures for housing electronic equipment and, more specifically, to an apparatus for mechanically connecting two such enclosures at an interface and for providing shielding to attenuate electromagnetic energy originating from within the enclosures.
2. Discussion of the Prior Art
Components of larger computer systems are typically housed in a series of separate cabinets or enclosures which stand upright on a floor. For example, the central processing unit (CPU), main memory and related input/output circuitry may be housed within one cabinet, while a disk drive or other mass storage device is housed in a separate cabinet. A primary reason for housing such components separately is that they often represent optional equipment, which may be purchased initially as part of a new computer system or subsequently to expand or enhance the system. Thus, in order to provide flexibility for configuring or reconfiguring a system to meet the requirements of a particular application, most components are housed separately so that they may be easily and quickly removed from or added to the system.
Frequently, it is necessary or desirable to join two separate enclosures together in such a way that the components housed within may be interconnected by cables or wires which provide communication paths, power, etc. To allow easy access for such interconnecting cables or wires, it is usually necessary to remove a portion of each enclosure, such as a side panel, to create an open path between the interiors of the enclosures.
One conventional device for joining two enclosures consists of a rectangular frame which is placed between and secured to the enclosures. The frame is sized to surround an opening exposed by the removal of the side panel of an enclosure and is therefore approximately the same size as the panel.
Such conventional frames present several disadvantages, however. First, because the frame is relatively large and thin, it lacks substantial structural integrity prior to installation. Consequently, storage and shipping costs are greatly increased due to the necessity of providing special packaging to protect the frame against damage and the substantial volume occupied by the frame.
Second, since the enclosure itself is often used as shielding against electromagnetic energy emanating from the enclosed circuitry, suitable shielding must be provided when a portion (side panel) of the enclosure is removed. If a rigid frame installed between two enclosures does not fit closely or does not include suitable shielding, increased emissions will escape into the ambient environment. Since maximum permissible emission levels are established by most governments, it is essential that actual emissions remain within the allowed maximum levels so that the product may be freely marketed throughout the world.
Third, each frame is sized to fit a particular size of enclosure and is generally not usable with other sizes of enclosures. Accordingly, different sizes of frames must be made and stocked if more than one size of enclosure is offered.
Finally, the frame may adversely impact the appearance of the enclosures by introducing a non-uniform "seam" between the enclosures.